[PATCH v1 3/6] drm/edid: Add cea_sad helpers for freq/length
From: Markus Schneider-Pargmann <msp@baylibre.com>
Date: 2021-09-06 19:41:16
Also in:
dri-devel, linux-mediatek
Subsystem:
drm drivers, drm drivers and misc gpu patches, the rest · Maintainers:
David Airlie, Simona Vetter, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Linus Torvalds
This patch adds two helper functions that extract the frequency and word length from a struct cea_sad. For these helper functions new defines are added that help translate the 'freq' and 'byte2' fields into real numbers. Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com> --- drivers/gpu/drm/drm_edid.c | 57 ++++++++++++++++++++++++++++++++++++++ include/drm/drm_edid.h | 18 ++++++++++-- 2 files changed, 73 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 81d5f2524246..2389d34ce10e 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c@@ -4666,6 +4666,63 @@ int drm_edid_to_speaker_allocation(struct edid *edid, u8 **sadb) } EXPORT_SYMBOL(drm_edid_to_speaker_allocation); +/** + * drm_cea_sad_get_sample_rate - Extract the sample rate from cea_sad + * @sad: Pointer to the cea_sad struct + * + * Extracts the cea_sad frequency field and returns the sample rate in Hz. + * + * Return: Sample rate in Hz or a negative errno if parsing failed. + */ +int drm_cea_sad_get_sample_rate(struct cea_sad *sad) +{ + switch (sad->freq) { + case CEA_SAD_FREQ_32KHZ: + return 32000; + case CEA_SAD_FREQ_44KHZ: + return 44100; + case CEA_SAD_FREQ_48KHZ: + return 48000; + case CEA_SAD_FREQ_88KHZ: + return 88200; + case CEA_SAD_FREQ_96KHZ: + return 96000; + case CEA_SAD_FREQ_176KHZ: + return 176400; + case CEA_SAD_FREQ_192KHZ: + return 192000; + default: + return -EINVAL; + } +} +EXPORT_SYMBOL(drm_cea_sad_get_sample_rate); + +/** + * drm_cea_sad_get_uncompressed_word_length - Extract word length + * @sad: Pointer to the cea_sad struct + * + * Extracts the cea_sad byte2 field and returns the word length for an + * uncompressed stream. + * + * Note: This function may only be called for uncompressed audio. + * + * Return: Word length in bits or a negative errno if parsing failed. + */ +int drm_cea_sad_get_uncompressed_word_length(struct cea_sad *sad) +{ + switch (sad->byte2) { + case CEA_SAD_UNCOMPRESSED_WORD_16BIT: + return 16; + case CEA_SAD_UNCOMPRESSED_WORD_20BIT: + return 20; + case CEA_SAD_UNCOMPRESSED_WORD_24BIT: + return 24; + default: + return -EINVAL; + } +} +EXPORT_SYMBOL(drm_cea_sad_get_uncompressed_word_length); + /** * drm_av_sync_delay - compute the HDMI/DP sink audio-video sync delay * @connector: connector associated with the HDMI/DP sink
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index 759328a5eeb2..bed091a749ef 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h@@ -361,12 +361,24 @@ struct edid { /* Short Audio Descriptor */ struct cea_sad { - u8 format; + u8 format; /* See HDMI_AUDIO_CODING_TYPE_* */ u8 channels; /* max number of channels - 1 */ - u8 freq; + u8 freq; /* See CEA_SAD_FREQ_* */ u8 byte2; /* meaning depends on format */ }; +#define CEA_SAD_FREQ_32KHZ BIT(0) +#define CEA_SAD_FREQ_44KHZ BIT(1) +#define CEA_SAD_FREQ_48KHZ BIT(2) +#define CEA_SAD_FREQ_88KHZ BIT(3) +#define CEA_SAD_FREQ_96KHZ BIT(4) +#define CEA_SAD_FREQ_176KHZ BIT(5) +#define CEA_SAD_FREQ_192KHZ BIT(6) + +#define CEA_SAD_UNCOMPRESSED_WORD_16BIT BIT(0) +#define CEA_SAD_UNCOMPRESSED_WORD_20BIT BIT(1) +#define CEA_SAD_UNCOMPRESSED_WORD_24BIT BIT(2) + struct drm_encoder; struct drm_connector; struct drm_connector_state;
@@ -374,6 +386,8 @@ struct drm_display_mode; int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads); int drm_edid_to_speaker_allocation(struct edid *edid, u8 **sadb); +int drm_cea_sad_get_sample_rate(struct cea_sad *sad); +int drm_cea_sad_get_uncompressed_word_length(struct cea_sad *sad); int drm_av_sync_delay(struct drm_connector *connector, const struct drm_display_mode *mode);
--
2.33.0
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